Inspection device and inspection method for detecting foreign bodies in a filled container

Abstract

An inspection device and an inspection method for detecting foreign bodies in a filled container, and having at least one inspection camera, a transport device for the at least section-by-section linear transport of the container and at least one vibration device for vibrating the container, where foreign bodies in the containers can be set in motion without complicated acceleration and retarding of the container and the movements can be registered and compared as single images by the inspection cameras even with a stationary camera position. The construction of the device is less space-consuming and less complicated than for machines of the rotary type and the detection of foreign bodies is more reliable than with conventional machines of the linear type.

The invention claimed is: 
     
       1. Inspection device for detecting foreign bodies present in a filled container in a vicinity of a container bottom, comprising:
 a) at least one inspection camera arranged such that it can take dark-field images of the container bottom from below; 
 b) a transport device for the at least section-by-section linear transport of the container; 
 c) at least one vibration device for vibrating the container and setting the foreign bodies in motion; and 
 d) at least one illumination device located below the transport device and below the vibration device, wherein the illumination device irradiates the container sideways such that the foreign bodies in the vicinity of the container bottom are irradiated. 
 
     
     
       2. Inspection device according to  claim 1 , wherein the vibration device comprises at least one vibrator for producing vibrations and a circumferentially running transmission belt for transferring the vibrations to the container. 
     
     
       3. Inspection device according to  claim 2 , wherein the vibrator is a motor with an unbalance. 
     
     
       4. Inspection device according to  claim 2 , wherein the vibration device comprises a slide rail and/or a roller unit which is in contact with the vibrator and the transmission belt. 
     
     
       5. Inspection device according to  claim 1 , wherein at least two vibration devices are provided which act on a side wall of the container from essentially opposite directions. 
     
     
       6. Inspection device according to  claim 1 , wherein the transport device comprises an upper and a lower pair of guide belts which hold the container off the ground in each case and the vibration device is set up such that it transfers vibrations to the container between at least one upper and one lower guide belt. 
     
     
       7. Inspection device according to  claim 6 , wherein the guide belts damp oscillations at an oscillation frequency of the vibration device. 
     
     
       8. Inspection device according to  claim 1 , wherein at least two inspection cameras are arranged one after the other in relation to the transport direction of the transport device and the image areas of the inspection cameras overlap. 
     
     
       9. Inspection device according to  claim 1 , wherein the illumination device is continuous light source. 
     
     
       10. Inspection device according to  claim 1 , wherein at least two illumination devices are provided which from a light corridor illuminating a container on both sides. 
     
     
       11. Inspection device according to  claim 1 , and an evaluation unit for the detection of foreign bodies through the comparison of image data from the inspection camera and a diversion device for diverting faulty containers. 
     
     
       12. Inspection method for the detection of foreign bodies present in a filled container in a vicinity of a container bottom, comprising:
 a) linear transporting the container at least section-by-section with a transport device; 
 b) vibrating the container side wall with a vibration device to set foreign bodies into motion located on the container bottom; 
 c) irradiating the container sideways with an illumination device located below the transport device and below the vibration device such that the foreign bodies in the vicinity of the container bottom are irradiated; and 
 d) acquiring light which has been deflected on the foreign bodies and taking dark-field images of the container bottom from below. 
 
     
     
       13. Inspection method according to  claim 12 , wherein triggered dark-field single shots of the container bottom are taken in step d) and:
 e) evaluating the acquired image data, wherein an image section is assigned in each case to the container bottom as an evaluation region and image data from the assigned evaluation regions are compared with one another to detect foreign bodies as differences in the compared image data; and 
 f) rejecting the container if at least one foreign body has been detected in it.